Cloud Peak Energy Inc. (NYSE:CLD), one of the largest U.S. coal producers and the only pure-play Powder River Basin (PRB) coal company, today announced that Colin Marshall, Cloud Peak Energy’s President and Chief Executive Officer, will speak at the Barclays CEO Energy-Power Conference at 3:05 p.m. (ET) on Thursday, September 6, 2012 in New York, New York. For additional investor information, please visit the investor relations section of the Cloud Peak Energy web site: www.cloudpeakenergy.com/investor-relations. About Cloud Peak Energy® Cloud Peak Energy Inc. (NYSE:CLD) is headquartered in Wyoming and is one of the largest U.S. coal producers and the only pure-play PRB coal company. As one of the safest coal producers in the nation, Cloud Peak Energy specializes in the production of low sulfur, subbituminous coal. The company owns and operates three surface coal mines in the PRB, the lowest cost major coal producing region in the nation. The Antelope and Cordero Rojo mines are located in Wyoming and the Spring Creek Mine is located near Decker, Montana. Cloud Peak Energy also owns rights to substantial undeveloped coal and complimentary surface assets in the Northern PRB, further building the company’s long-term position to serve Asian export and domestic customers. With approximately 1,600 employees, the company is widely recognized for its exemplary performance in its safety and environmental programs. Cloud Peak Energy is a sustainable fuel supplier for approximately 4% of the nation’s electricity.